AusBonsai

Hello everyone. I have a Golden Ash I bought online as bare-root stock and so I was unable to select a nice looking graft for the future. I am hoping for some opinions on what I should do. In this pic, it is now ~6 years old (I assume the bare root tree was 2 years when I got it), so for the moment, I've just let it grow out and then loosely pruned back, and then repeat for a few years. I was initially trying to ground layer with an extra pot cut into a ring, with a wire wrapped around the trunk (below the graft, as seen in pic) and get some higher roots but now I am unsure. Part of me likes the vigor and disease resistance (etc) that the Ash rootstock provides, but it does go quite craggly whereas the golden ash does not really do that - so the graft will almost always be visible (hence the attempt to raise the root plane). For bonsai purposes, should I abandon the graft altogether and try to layer the golden roots only? Does anyone have experience with this variety and how poorly the natural roots might be?
I was planning on chopping the tree here this spring.
Regardless of what layer I try to do (above rootstock or below rootstock), my final question is whether the trunk chop is a good idea post layering, or whether I should be less aggressive in my pruning for the upcoming season.
Any thoughts very much appreciated!

I don't know the species well but I would try both. There is definitely room for an air layer above your proposed chop point. If you're greedy and patient you could even do it twice. -Air layer the top this year and the middle next year.

I agree with the air layer idea. Best of both worlds! Try to make the incision at a bit of an angle to give the lower trunk some initial movement.

I have worked with Ash but not golden and answer to your final question first, I think that cut will help heaps with taper. I have done that before and while it takes a few years the taper uoh get is superb.
I would however suggest that you just plant it in the ground and let the grafted tree grow crazy for a couple of years and then take a few grafts from it. By then your base of the ash will also have grown really well.